Niaspan ER and muscle weakness

I've been taking prescription Niaspan for about 2 1/2 months now and was warned by my doctor about the flushing. For the first month and a half all was fine but one night my wife and I were reading in bed when I suddenly felt like my face was on fire. My wife grew alarmed and said that I looked beet red. Within five minutes the feeling and red appearance had spread all over my body. We went over the day to see if I had done anything out of the ordinary and realized that I had eaten shrimp and clams for dinner at a Chinese buffet. I chalked it up to that. We shut off the light and went to sleep and when I woke up in the middle of the night to let the dog out I was back to normal. Last night was the second time now this has happened only this time I was sound asleep when it hit. I woke up suddenly to discover the same symptoms and it was painful to move even a finger. As soon as I moved ANYTHING I felt like I was being stung everywhere. My skin too was hot to the touch. I went on an agonizing walk to the bathroom to see what I looked like and I was fire-engine red from head to toe. Again I managed to go back to sleep but I still have some lingering effects of tingling even now as I write this. My wife told me this morning that I was being melodramatic. I told her she should try it and get back to me.